Modular construction of size-selected multiple-core Pt-TiO2 nanoclusters for electro-catalysis

摘要

Size-selected binary platinum-titanium dioxide (Pt-TiO2) clusters have been generated using a magnetron sputtering gas condensation cluster source and imaged using a Scanning Transmission Electron Microscope (STEM) in High Angle Annular Dark Field (HAADF) mode. The core-shell clusters exhibit a Pt core of preferred size 30 +/- 6 atoms (1 nm), embedded in an oxidised Ti shell, independent of the overall cluster size (varied between 2 nm and 5 nm). Smaller clusters, with mass <= 50000 Daltons, show a single Pt core while larger clusters, >= 55000 Daltons, feature multiple Pt cores, either isolated or aggregated within the TiO2 shell. These clusters may have applications in solar hydrogen production; preliminary work indicates catalytic active in the hydrogen evolution reaction.